[PATCH 3.14 85/94] drm/i915: fix display power sw state reporting

From: Greg Kroah-Hartman
Date: Mon Jul 07 2014 - 20:27:16 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Imre Deak <imre.deak@xxxxxxxxx>

commit b8c000d9bf23e7c1155ef421f595d1cbc25262da upstream.

Atm, we refcount both power domains and power wells and
intel_display_power_enabled_sw() returns the power domain refcount. What
the callers are really interested in though is the sw state of the
underlying power wells. Due to this we will report incorrectly that a
given power domain is off if its power wells were enabled via another
power domain, for example POWER_DOMAIN_INIT which enables all power
wells.

As a fix return instead the state based on the refcount of all power
wells included in the passed in power domain.

References: https://bugs.freedesktop.org/show_bug.cgi?id=79505
References: https://bugs.freedesktop.org/show_bug.cgi?id=79038
Reported-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Damien Lespiau <damien.lespiau@xxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/intel_pm.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5138,10 +5138,25 @@ bool intel_display_power_enabled_sw(stru
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct i915_power_domains *power_domains;
+ struct i915_power_well *power_well;
+ bool is_enabled;
+ int i;
+
+ if (dev_priv->pm.suspended)
+ return false;

power_domains = &dev_priv->power_domains;
+ is_enabled = true;
+ for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
+ if (power_well->always_on)
+ continue;

- return power_domains->domain_use_count[domain];
+ if (!power_well->count) {
+ is_enabled = false;
+ break;
+ }
+ }
+ return is_enabled;
}

bool intel_display_power_enabled(struct drm_device *dev,


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